In recent years, along with the development of line of sight estimation techniques, research and development for improving the accuracy of the line of sight estimation have been performed. In the case of the line of sight estimation technique in which an eyeball is irradiated with light and a reflection point (a bright spot) generated by the light is used, it is required to control a light source according to the exposure time. Here, Prior Literature 1 discloses a technique of setting a control time of the light source according to the exposure time.